674 PHILOSOPHICAL TRANSACTIONS. [aNNO I796. 



public. The parts which in the whale correspond in situation and office with 

 the mesenteric glands of other animals, differ considerably from those glands in 

 structure. These peculiarities are not only curious in themselves, but are illus- 

 trative of circumstances, hitherto esteemed obscure, in the anatomy and economy 

 of the lymphatic glands in general. The animal, from which the parts that I am 

 going to describe were taken, was a male, of the genus named by Linneus 

 balaena. 



Being desirous of making an anatomical preparation, to show the distribution 

 of tiie mesenteric vessels and lacteals of the whale, I procured for this purpose a 

 broad portion of the mesentery with the annexed intestine; and proceeded in the 

 first place to inject the blood-vessels. The mesentery had been cut from the 

 animal as close to the spine as possible; had a less portion been taken away, 

 the parts which I am about to describe would have been left with the body, for 

 they are situated on the origin of the blood-vessels belonging to the intestines; 

 and this perhaps is the reason why they have not been observed before. When 

 I threw a red-coloured waxen injection into the mesenteric artery, I saw it mean- 

 dering in the ramifications of that vessel ; but at the same time I observed it col- 

 lecting in several separate heaps, about the root of the mesentery, which soon 

 increased to the size of eggs. At the time, I imagined that the vessels had been 

 ruptured, and that the injection in consequence had become extravasated ; but I 

 was conscious that no improper degree of force had been used in propelling the 

 injection. I next threw some yellow injection into the vein, when similar phe- 

 nomena occurred ; the branches of the vein were filled, but at the same time 

 the masses of wax near the root of the mesentery were increased by a further effu- 

 sion of the injection. These lumps had now acquired a spherical form, and 

 some of them were of the size of an orange. 



After the injection had become cold, I cut into the mesentery, in order to 

 remove these balls of wax ; when I found that they were contained in bags, in 

 which I also observed a slimy and bloody-coloured fluid. On the inner surface 

 of these bags a great number of small arteries and veins terminated ; from the 

 mouths of which the injection had poured into their cavities. There were 7 of 

 these bags in that piece of mesentery which I had to examine ; but I am not 

 able to determine what number belonged to the animal ; for I do not know whe- 

 ther the portion of mesentery that I possessed was complete. Having removed 

 the injection from these bags, I observed on the inside of them a soft whitish 

 substance, apparently containing a plexus of lacteal vessels. This substance 

 entered the bags at that part of them which was nearest to the intestines, and 

 went out at the part next to the spine. I now poured some quicksilver into 

 those lacteals which appeared to lead to this soft substance : the quicksilver soon 

 entered the vessels which were contained in it, and thus its nature was ascer- 



